in reply to Adding an nslookup to a log script

Here is one way to get the name. 
use Socket;
my $iaddr = inet_aton('64.236.172.30');
my $name  = gethostbyaddr($iaddr, AF_INET);
print $name;

[download]
read perldoc -f gethostbyaddr
Boris

In Section Seekers of Perl Wisdom